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Stack #130115
Question | Answer |
---|---|
What is the number of waves passing a given point per unit of time? | frequency |
what is the distance between 2 successive crests or troughs? | wavelength |
As the energy of electromagnetic radiation increases, what happens to the frequency, wavelength, and speed? | increases, decreases, stays the same |
The shape of all electromagnetic radiation is what? | sine curve |
The normal range of diagnostic x-ray photon wavelength is what? | 0.1 to 1.0 Angstrom |
The unit of energy of a photon is the what? | eV (electron volt) |
Does the wavelength of the photon impact beam quality? | yes |
Does the wavelength of the photon impact beam penetration? | yes |
Does the wavelength of the photon impact beam energy? | yes |
The production of x-ray _______ results from the rapid deceleration of fast moving __________ interacting with the target materials? | photons, electrons |
Is the quality or penetrability of the x-ray photon is affected by changes in KVP? | yes |
Is the quality or penetrability of the x-ray photon is affected by changes in mA? | no |
Is the quality or penetrability of the x-ray photon is affected by changes in time? | no |
Is the quality or penetrability of the x-ray photon is affected by changes in distance? | yes |
The dual nature of x-ray energy is the concept that the photons behaving as what two things? | particle and a wave |
What is the charge of the cathode? | negative |
What is the charge of the anode? | positive |
The cathode consists of what two things? | filament and a focusing cup |
The process of boiling electrons from the filament is what? | thermionic emissions |
The filament is made of what? | tungsten |
The focusing cup is made of what? | nickel |
The anode (target) is made of what? | tungsten and rhenium alloy |
What stops the electrons abruptly to form x-rays? | target |
What is the stream of electrons that crosses the tube from the cathode to the anode? | tube current |
The rotating anodes rotate at a set speed at what range? | 3,000 to 10,000 RPM |
Why is a rotating anode better than a stationary? | Can withstand high heat levels |
What components in the tube make the anode rotate? | stator and rotor |
What is the physical area of the target that is bombarded with electrons during an exposure. | actual focal spot |
Why do we want the x-ray tube to be a vacuum? | Allows efficient flow of electrons from the cathode to anode |
What is the major purpose of the tube housing? | Reduce leakage radiation |
What are the two interactions that take place on the target tube? | Bremsstrahlung and Characteristic |
In the Bremsstralung interaction, the incident electron interacts with what and results in what? | electromagnetic field surrounding the nucleus which causes the electron to slow down and strong nuclear force keeps them apart and deflects electron |
For Bremsstrahlung interaction, what determines how much energy is given up? | amount of energy given up depends on how close it comes to the nucleus. the closer it comes the more energy |
Below 70 KVP (with a tungsten): what percentage of the beam is characteristic and what percent is Brems? | O%; 100% |
For the Characteristic interaction, which electron is ejected and what happens because of it? | the inner shell electron is ejected causing the outer electrons to drop down to fill the holes and energy is released to do this. |
Above 70 KVP, what percentage of the beam is characteristic and what perctage of the beam is Brems? | 15% is characteristic and 85% is Brems |
What is the highest energy of the photon beam when .05 sec, 400 mA, and 70 KVP are utilized as the exposure factors? | 70 KVP |
When electrons are boiled off of the filament, they form cloud around the filament called what? | space charge |
When electrons strike the target, what percentage is heat and what percentage is x-ray? | 99% heat and 1% x-ray |
KVP represents what and impacts what of the beam? | potential difference; quality |
As KVP increases, beam quality does what, and the penetrability of the beam does what? | increases, increases |
MA is the unit used to measure what? | tube current |
With an increase in mA, the quantity of electrons does what, and the quantity of photons produced does what? | increase, increase |
With an increase in exposure time, the quantity of electrons does what and the quantity of photons produced does what? | increase, increase |
The line focus principle describes the relationship between what two things? | actual focal spot size and effective focal spot size |
What is the actual focal spot? | size of the area on the anode target that is exposed to electrons from the tube current |
What is the effective focal spot? | focial spot size as measured directly under anode target |
The smaller the anode angle results in what effective focal spot? | smaller |
The anode hill effect describes how the x-ray beam has greater intensity on which side of the x-ray tube? | cathode |
What is utilized to harden the beam? | Filtration |
What plus what equals total filtration? | inherent filtration plus added filtration |
Regulations state that tubes operating over 70 KVP must have a total filtration of what? | 2.5 mm Aluminum |
What is used to measure filtration? | (HVL) Half-value layer |
What is the amount of heat produced by any given exposure? | Heat unit (HU) |
What is the formula for heat units? | mA x time x KVP x generator factor = HU |
Who and when were x-rays discovered? | Nov 8, 1895 |
Wavelength and frequency is directly or inversley proportional? | inversley |
What is needed to make x-rays? | source of electrons, way to accelerate the electrons, and way to stop the electrons |